Definition of Friars
An order of religious persons, of whom there were four principal branches, viz.: (1) Minors, Grey Friars, or Franciscans; (2) Augustines; (3) Dominicans, or Black Friars; (4) White Friars, or Carmelites, from whom the rest descend.
That's the definition of Friars in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.